Networking a Mac using a DHCP server on WinNT

Posted on 1998-02-11
Last Modified: 2013-11-13
We have WindowsNT network.  We use a DHCP server to assign IP addresses to the Win boxes.  We also have one Mac running OS8 (Open Transport).  The Mac has an Ethernet card and we would like to get the Mac connected to the WinNT Exchange server for email.  Microsoft's Technet says this is possible, providing an IP address can be assigned to the Mac.  We successfully get an IP address for the Mac using the method Technet recommends.  However, we have no DNS, so the Mac must use a Hosts file to define the name resolution for the mail server.  The Exchange server is called "server2" (no additional domains in the address) and has a four-part IP address.  Open Transport doesn't appear to be able to resolve the simple name "server2" to a valid IP address.
The question is - how must the Hosts file be configured to make this work?  It obviously hinges around how the Hosts file is interpreted by the Mac when trying to contact the Exchange server.

Question by:sejs2
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Expert Comment

ID: 1581743
Just setup DNS server on your NT server, to resolve your local host name. Specify DNS server's IP address in you Mac's IP configuration.

To setup DNS on NT, just open Control Panel/Network/Services tab, add DNS Server service.

Author Comment

ID: 1581744
We don't want to implement DNS services for one Mac because it puts some overhead on the NT 3.51 server and increases the complexity of the networking here.  Ideally, the hosts file would be sufficient.


Expert Comment

ID: 1581745
I did some searching for you, and came up with this info from Apple:

Open Transport/TCP supports one or more HOSTS file, stored in the System Preferences folder, that may be used to supplement and/or customize the domain name resolver's initial cache of information. The selected file is opened and parsed when Open Transport/TCP is initialized. As with MacTCP, the supported HOSTS file features follow a subset of the Domain Name System Master File Format (RFC 1035).

Supported features include blank lines, comments (indicated by a semicolon), and data entry. Comments may begin at any location in a line; they may follow data entry on the same line. A comment extends from the semicolon to the end of the line. Data entry must follow the format:

<domain-name> <rr> (<comment>)

where <domain-name> is an absolute or Fully Qualified Domain Name, and where

<rr> = (<ttl>) (<class>) <type> <rdata> OR (<class>) (<ttl>) <type> <rdata>

The only <class> currently supported is IN (Internet Domain); <ttl>, time to live, indicates the record's configured lifetime in seconds; and <type> can be A (host address), CNAME (canonical name of an alias), or NS (name server). If <ttl> is not present the entry is assumed to have an infinite lifetime; this may also be indicated by specifying a value of minus-one (-1). $INCLUDE and $ORIGIN are not supported.

Open Transport/TCP is more stringent regarding the content and format of the HOSTS file than was MacTCP, which permitted violation of the FQDN requirement for <domain-name>. For instance, this format:

charlie              A

which was acceptable to the MacTCP DNR, is no longer permitted because of the use of domain search lists in Open Transport/TCP (charlie could potentially exist in any or all of the configured domains). To accomplish the same effect, use this format instead:

charlie              CNAME  A

This associates the local alias charlie with the fully qualified domain name, and resolves it to the address Use of local aliases is limited to CNAME entries; NS and A entries must use fully qualified domain names.

If a HOSTS file is used, every effort should be made to keep it as small as possible and to only include entries that will be accessed frequently. This reduces the total memory footprint required to cache the DNS information and minimizes the need to maintain and update the HOSTS files as system information changes over time.

In order to activate a HOSTS file, the Advanced or Administrator mode must be used to select the desired file. The text file must already exist; it could have been created with any text editor or word processor. The HOSTS file is tied to the selected configuration. An administrator might, for example, specify different HOSTS files for use when connecting via Ethernet to the campus LAN and when dialing-in from a remote location.

I hope this answers your questions.
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Author Comment

ID: 1581746
I've seen this info before and tried all of that (unsuccessfully)!  (Thanks though).  I also stumbled across this on Technet yesterday (and I mean stumbled - heaven knows how they index that stuff!):

"Q: Can Open Transport/TCP act as a WINS client to a Windows NT
Advanced Server?
A: No, not at this time. The Microsoft WINS server is dependent on Microsoft extensions to TCP/IP (requiring NetBIOS support) that provide some automation for assignment and registration of IP host and domain names."

Because we're using WINS, it seems unlikely that we'll ever get it to work down this route.  Which brings us neatly back to bbao's response...
bbao, if you're still watching, how easy is it to set up the DNS service on NT (minutes, hours, other configuration)?  How much extra overhead does it place on the network given we're using Hosts files at the moment?

Accepted Solution

caeisenb earned 200 total points
ID: 1581747
Much easier than that: Set up MacDNS on the Mac!

I set one up here in less than 10 minutes!  It takes up almost no overhead, and can run on the same machine you are using.

Get it from

Install it, configure it.

Then, simply set the Mac it is running on to use itself as the DNS server.

I hope this answers your questions!


Expert Comment

ID: 1581748
You should be able to enter the IP in the Exchange profile and forego DNS/host files alltogether.  In the profile, under Server Name, enter the IP of the Exchange server instead of the name.  Exchange should be able to work w/o the actual name as long as it has the IP.

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